xfs: factor extsize hint checking out of xfs_ioctl_setattr

The extent size hint change checking is fairly complex, so isolate
that into it's own function. This simplifies the logic flow of the
setattr code, making it easier to read.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_ioctl.c

@@ -1098,6 +1098,51 @@ out_cancel:
 	return ERR_PTR(error);
 }
 
+int
+xfs_ioctl_setattr_check_extsize(
+	struct xfs_inode	*ip,
+	struct fsxattr		*fa)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+
+	/* Can't change extent size if any extents are allocated. */
+	if (ip->i_d.di_nextents &&
+	    ((ip->i_d.di_extsize << mp->m_sb.sb_blocklog) != fa->fsx_extsize))
+		return -EINVAL;
+
+	/*
+	 * Extent size must be a multiple of the appropriate block size, if set
+	 * at all. It must also be smaller than the maximum extent size
+	 * supported by the filesystem.
+	 *
+	 * Also, for non-realtime files, limit the extent size hint to half the
+	 * size of the AGs in the filesystem so alignment doesn't result in
+	 * extents larger than an AG.
+	 */
+	if (fa->fsx_extsize != 0) {
+		xfs_extlen_t    size;
+		xfs_fsblock_t   extsize_fsb;
+
+		extsize_fsb = XFS_B_TO_FSB(mp, fa->fsx_extsize);
+		if (extsize_fsb > MAXEXTLEN)
+			return -EINVAL;
+
+		if (XFS_IS_REALTIME_INODE(ip) ||
+		    (fa->fsx_xflags & XFS_XFLAG_REALTIME)) {
+			size = mp->m_sb.sb_rextsize << mp->m_sb.sb_blocklog;
+		} else {
+			size = mp->m_sb.sb_blocksize;
+			if (extsize_fsb > mp->m_sb.sb_agblocks / 2)
+				return -EINVAL;
+		}
+
+		if (fa->fsx_extsize % size)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+
 STATIC int
 xfs_ioctl_setattr(
 	xfs_inode_t		*ip,
@@ -1160,49 +1205,16 @@ xfs_ioctl_setattr(
 		code = xfs_qm_vop_chown_reserve(tp, ip, udqp, NULL, pdqp,
 				capable(CAP_FOWNER) ?  XFS_QMOPT_FORCE_RES : 0);
 		if (code)	/* out of quota */
-			goto error_return;
-	}
-
-	/* Can't change extent size if any extents are allocated. */
-	code = -EINVAL;
-	if (ip->i_d.di_nextents &&
-	    ((ip->i_d.di_extsize << mp->m_sb.sb_blocklog) != fa->fsx_extsize))
-		goto error_return;
-
-	/*
-	 * Extent size must be a multiple of the appropriate block size, if set
-	 * at all. It must also be smaller than the maximum extent size
-	 * supported by the filesystem.
-	 *
-	 * Also, for non-realtime files, limit the extent size hint to half the
-	 * size of the AGs in the filesystem so alignment doesn't result in
-	 * extents larger than an AG.
-	 */
-	if (fa->fsx_extsize != 0) {
-		xfs_extlen_t    size;
-		xfs_fsblock_t   extsize_fsb;
-
-		extsize_fsb = XFS_B_TO_FSB(mp, fa->fsx_extsize);
-		if (extsize_fsb > MAXEXTLEN)
-			goto error_return;
-
-		if (XFS_IS_REALTIME_INODE(ip) ||
-		    (fa->fsx_xflags & XFS_XFLAG_REALTIME)) {
-			size = mp->m_sb.sb_rextsize << mp->m_sb.sb_blocklog;
-		} else {
-			size = mp->m_sb.sb_blocksize;
-			if (extsize_fsb > mp->m_sb.sb_agblocks / 2)
-				goto error_return;
-		}
-
-		if (fa->fsx_extsize % size)
-			goto error_return;
+			goto error_trans_cancel;
 	}
 
+	code = xfs_ioctl_setattr_check_extsize(ip, fa);
+	if (code)
+		goto error_trans_cancel;
 
 	code = xfs_ioctl_setattr_xflags(tp, ip, fa);
 	if (code)
-		goto error_return;
+		goto error_trans_cancel;
 
 	/*
 	 * Change file ownership.  Must be the owner or privileged.  CAP_FSETID
@@ -1247,7 +1259,7 @@ xfs_ioctl_setattr(
 
 	return code;
 
-error_return:
+error_trans_cancel:
 	xfs_trans_cancel(tp, 0);
 error_free_dquots:
 	xfs_qm_dqrele(udqp);